Model 10 code confusion

I think you mean Product Codes - a code that designates barrel length, model, finish, perhaps sights, or other features. The assembly numbers were used to keep major components together during the manufacturing process, these numbers ensure the right yoke was married to the right frame, cylinder, etc.

Before the frame was serial numbered the yoke was fitted to it, and after the parts were blued (or whatever) the had to have a way to get the pre-fitted yoke back into the right frame. The did this by stamping a (so called) assembly number on the yoke and frame, and sometimes inside the sideplate, although the sideplates were usually stamped with the serial number.

Assembly numbers are not related to any other numbers.

This becomes further confusing, because at a later date they eliminated the assembly number, and moved the serial number to where it used to be on the frame. So when lots of people look at an older revolver they mistake the assembly number for the gun's serial number - especially if the bottom of the butt is covered by the stocks. This can make a first class mess.

After 1957 they also marked the model number under the assembly number, and then even later when the serial number took the place of the assembly nunber they stamped it under that.

No, I have no idea who is on first...

What would be the year for a C637XXX?

SCSW says 1954 - 1956, so it should be a pre-10.

"Will5A1 SCSW says 1954 - 1956, so it should be a pre-10. "
Thanks for date but as to pre-10 when you open the cylinder there's 10-5 written inside. So it says 10-5. My only concern is that I recall somewhere reading that from 10-5 forward you could safely fire +P rounds.

Thanks again.

Thanks to all for info; as posted a couple of years ago, I got this gun from my father-in-law and it had some rust and required a little work from the Armory in Virginia Beach but is exceptionally accurate.